The power switches used to form such inverters are almost exclusively executed in a three-phase bridge configuration, as shown in FIG. 13. Such an inverter generates multi-phase alternating current with three phases U, V, and W, from a dc voltage source. The antiparallel switching of power switches T1 to T6, shown in FIG. 13, using corresponding diodes, enables four-quadrant operation, and thus allows many applications for such an inverter circuit.
The disadvantage of such an inverter circuit is that in the event of a short circuit across two switches, e.g. T1 and T2, extremely large energy flows occur, which typically causes complete destruction of the inverter, perhaps even starting a fire which leads to the destruction of all connected system components.